The present invention relates to stamps, and relates more particularly to a rotary stamp for stamping marks on things by rolling an impression wheel.
FIG. 4 shows a rotary stamp according to the prior art which comprises a casing having an upright rod transversely disposed on the inside and an axle housing disposed below the upright rod, a cover board having a pin hole, which receives the upright rod of the casing, and an axle housing corresponding to the axle housing of the casing, an ink roller mounted around the upright rod of the casing, a stamping wheel peripherally covered with a ring-shaped stamp and having a center axle hole, a wheel axle inserted through the center axle hole and having two pin holes at two opposite ends, two locating blocks respectively received in the axle housings of the casing and the cover board and having each a horizontal rod respectively fitted into either pin hole of the wheel axle and a vertical rod supported on a respective spring inside either axle housing. The casing and the cover board are fastened together by fastening respective retainer rods on the casing into respective retaining holes on the cover board. When the ring-shaped stamp is turned over something to mark it, the springs on the locating blocks are compressed, causing the ring-shaped stamp contact the ink cylinder. This structure of rotary stamp consists of a lot of parts, therefore its assembly process is complicated and its manufacturing cost is high. Another drawback of this structure of rotary stamp is that the springs may fail to work properly after long uses, causing the ring-shaped stamp unable to contact the ink roller smoothly. When this problem occurs, the rotary stamp can no longer make a clear mark on things. Still another drawback of this structure of rotary stamp is that the ink cylinder is made from cotton cloth which absorbs less amount of ink and cannot evenly apply ink to the surface of the ring-shaped stamp. A yet further drawback of this structure of rotary stamp is that the retainer rods may be broken easily when they are fastened to or disconnected from the retaining holes on the cover board.